John 14:19-20 "A little while longer and the world will see Me no more, but you will see Me. Because I live, you will live also. At that day you will know that I am in My Father, and you in Me, and I in you."
Just after this last sermon, our Lord Jesus was arrested and then crucified. On the third day our Lord rose from the dead and lives, so that we (after our old men or flesh have been crucified) will also live in His new resurrected and abundant live.
Gal 2:20 I have been crucified with Christ; it is no longer I who live, but Christ lives in me; and the life which I now live in the flesh I live by faith in the Son of God, who loved me and gave Himself for me.
After His death the world can no longer see Him any more. But after His resurrection, He appeared to His disciples many times to encourage and strengthen their faith in Him. He also told them that on a particular day they will understand and know His teaching: I am in My Father, and you in Me, and I in you.
Luke 24:45-49 And He opened their understanding, that they might comprehend the Scriptures. Then He said to them, "Thus it is written, and thus it was necessary for the Christ to suffer and to rise from the dead the third day, and that repentance and remission of sins should be preached in His name to all nations, beginning at Jerusalem. And you are witnesses of these things. Behold, I send the Promise of My Father upon you; but tarry in the city of Jerusalem until you are endued with power from on high."
So before His ascension, He taught them to enlighten their understandings of the everlasting gospel and to wait for the Promised of the Father - the baptism of the Holy Spirit.
Luke 24:51-52 Now it came to pass, while He blessed them, that He was parted from them and carried up into heaven. And they worshiped Him, and returned to Jerusalem with great joy,
On the day of His Ascension, when His disciples saw Him being lifted up to heaven, they knew that Jesus is the Father Himself (I am in the Father). Then, they believed also in the Promised of the Father and that soon they would be baptized with the Holy Spirit in Jerusalem.
Acts 1:4-5 And being assembled together with them, He commanded them not to depart from Jerusalem, but to wait for the Promise of the Father, "which," He said, "you have heard from Me; for John truly baptized with water, but you shall be baptized with the Holy Spirit not many days from now."
They knew that at the baptism of the Holy Spirit, the Holy Spirit must first come to dwell in their physical bodies (I in you). Then the Holy Spirit will completely immersed their spirit in His Spirit (you in Me) just like in the baptism with water when their physical bodies were completely immersed in water.
Hallelujah, all these few prophecies were fulfilled after His crucifixion and on the day of Ascension this was fulfilled- 'At that day you will know that I am in My Father, and you in Me, and I in you'.
When Christ is in us (I in you), it is the hope of glory. When we are in Christ (you in Me), He is literally carrying us by taking over all our problems, sorrows, sicknesses, regrets, worries, sufferings, etc. and replacing them with His love, peace, joy, assurances, faith, etc. Only then we can confess that we are truly living in His abundant life.
Brethren, the bible is truly the word of God and is written by the Holy Spirit. It is filled with truth. Read it for your guidance and blessings. Amen